Smoking Status in Relation to Clinicopathological Characteristics, Oncological Outcome, and Presence of Second Primary Lung Cancer in Patients with Bladder Cancer: A Population-based Registry Study

Objective: To evaluate the relationship between smoking status and clinicopathological characteristics and oncological outcome in bladder cancer (BC) patients and those with concomitant BC and lung cancer (LC) who developed BC or LC as a second primary cancer during their survivorship.Materials and Methods: A total of 2621 BC patients registered in the Turkish Urooncology Association Bladder Cancer Database between 2001 and 2021 were retrospectively analyzed. Patients were divided into two groups: those with BC only (BC group, n=2568) and those with concomitant BC and LC (BLC group, n=53). Data on patient demographics and smoking status (active smoker, former smoker, non-smoker) were recorded, as were the clinicopathological characteristics and oncological outcomes with respect to smoking status.Results: Active smokers comprised 50.5% and 49.1% of patients in the BC and BLC groups, respectively. The percentage of former smokers was 14.3% and 13.2% and percentage of non-smokers was 31.4% and 18.9% in the BC and BLC groups, respectively. In both BC and BLC groups, a higher percentage of males than females were active smokers (45.8% vs. 4.6% in BC and 47.2% vs. 1.9% in BLC). In the BLC group, the percentages of active smokers, former smokers and non-smokers in the BC first group were 56.0%, 24.0% and 20.0%, respectively, whereas the corresponding ratios in the LC first group were 50.0%, 8.3%, and 41.7%, respectively. The presence of smoking (active or former) vs. non-smoker status was associated with more advanced clinicopathological characteristics and poor oncological outcomes in both BC and BCL groups.Conclusions: This population-based registry study in patients with BC revealed the presence of smoking history (active or former) in almost two-thirds of patients in both BC and BLC groups, which was associated with more advanced clinicopathological characteristics and poor oncological outcomes in both BC and BCL groups.